Relief valve for kitchen boilers and the like



E. F; DONNELLY RELIEF VALVE FOR KITCHEN BOILERS AND THE LIKE Filed April1, 1927 Q lnv e nfqn Edward F Donnelvl xww l Patented Ma 22', 192a abovea predetermined EDWARD :2. Dominant, or mALnnN, massacnusn'rrs BELIEFVALVE FOR KIT CHEN BOILERS AND THE Application filed April 1, 1827.Serial Hal 80,165. 7

I This invention relates to a relief valve such as is used onkitchenboilers and the likeand especially to a relief valve of that typewhicl 'has incorporated therein a fusible member adapted to fuse in casethe temperature within the boiler rises above a predetermined point,fusing of the fusible member affording a relief to excessive pressurewhich accompanies excessive temperature. One of the objects of myinvention is to providea novel relief valve in which the valve itself ismade of fusible metal so that in case the temperature of the boilerrises oint the valve will melt thus'allowing a relief to the highpressure accompanying the abnormal tempera.- ture.

Another object of the invention is to pro- 1 vide a novel relief valveand seat which seat or'soc'k'etfor the lower end of the s ring a maklnga tight has a metal to-metal contact.

The particular features wherein the invention resides will be more fullyhereinafter set forth andthen pointed out in the appended claims. I

In the drawings, Fig. 1 is asectional view of a 'i'eliefvalve embodyingmy invention;

Fi 2 is a perspective view of the valve mem er.

In the drawings 1 indicates a portion of a container to'which a reliefvalve is applied. This container may be a kitchen boiler or any othersimilar receptacle.

The relief valve is rovided witha Body portion 2 to one end of which isscrew threaded a combined valve sea-t and coupling member 3, said member3 having the exteriorly screw-threaded portion 4' adapted to have ascrew-threaded connection with the container 1 and also being provided.

face 7. i The valve member is indicated "at 8. The lower end of thevalve member frusto-conical in shape and the upper end is cylindrical inshape, said upper end being recessed axially "as shown'at 9 to provide a10 by which the valve is yieldingly he d to its seat. The'upper end ofthe spring 10 engages a capmember 11 whichus screw threadedinto theupper end of the body 2, said cap member having the guiding pin 12depending therefrom which extendsinto the upper end ofthe spring andforms means the valve would ,,be liable to stick.

this herein by providing a tapering or cgnemetal which is fitted overand formsithe for centcringthe spring and retaining it in its properposition. The recess 9 is rela tlve y deep T so that the walls of therecess,

rich constitute an annular flange, extend do w ell up on the spring. Itwill be noted that the spring is of a diameter to substantially fill therecess 9 and as a considerable portion a of the spring is received in.the recess the 00- action of the walls of the recess with the as springserves to hold the valve in propervertical position. i The deviceoperates as a relief valve in the usual manner. The spring 10 normallyholds the valve a ainst the valve seat 5, said sprin m being of su cienttension or strength to hold the valve seated against the normal pressurein the boiler. If the pressure exceeds the normal pressurethen suchexcessive pressure will lift the valve 8 thereby compressing the mspring 10 and the .liguid 1n the boiler may. escape through the ischargeport 13 into whitcih a discharge pipe may be screwed if desire i In thepresent invention. the valve 8 is so made of fusible metal which has amelting point at a temperature above that. corresponding to the normalworking pressure in the boiler 1 butv below that corresponding to adangerous ressure' or 7 one which is 83 liable to burst t e boiler. If.the boiler should become overheated and the valve 8 should fail to-opentorelieve any excessive pressure that might develop in the boiler due toits overheated .condition the excessive temperature will fuseor melt thevalve 8 thus relieving the pressure in the boiler inthe same waas if thevalve had opened. Fusible meta is relatively soft and 1f the portion ofthe valve which engaged the sharp corner of the valve seat had a surfaceof; this fusible metal-there is danger that thee pressure of the springagainst the valve would embed the sharpcornerxof the valve seat intotherelatively soft metal so that To guard against-this I propose to providethe cone surface of my valve with a metal which is harder than thesoft'fusible metal of the body ofthe' valve and one which while 'ointwith the right angular valve seat 5 wil nevertheless: not be'cut or. I Iindgnted by the valve seat-thus retaining the v true fit betweentheseparts. Iaccomplisli shaped shell 14 of'brass or. s'om' similar" for along time.

face of the cone-shaped ortion of the valve. This construction, thereore, provides a fusible valve having a cone-shaped lower end to engagethe valve seat which is covered wlth a acket or shell of metal harderthan the fusible metal of the valve.

The metal-to-metal contact between the,

valve and the valve seat is hi hly advantageous because it rovid'es a vave which is very vmuch less lia le to stick than a valve in whch one ofthe contacting members is of soft material. In many relief valveseither. the valve seat or the portion of the valve engaging the seat isof rubber com- In valves of only there is very little danger that thevalve will stick to its seat and by havin .the surface of the valve ofthe harder meta this danger is still further reduced and thuspractically eliminated.

I In my improved valve the spring 16 is -re-' tained in position at itsupper end by the pin 12 and at its lower end by the walls of the recess9. In other words, the spring is retained in position at one end by the1 cap 11 and at the other end by the valve 8.

I will preferably extend the shell 14 slightly above the base of theconical port-ion of the valve so that thefupper edge 15 of the shellpresents a circular portion which embraces and reinforces the valve atthis point. This reinforcing portion 15 ofthe shell serves to preventthe relatively soft metal of the valve from spreading radially near thebottom of the recess dueto the pres- -sure of the spring against it.

One advantage of this construction is that if the valve becomes fused byhigh temperature the valve can only be put again into working positionby supplying an entirely new valve since the entire valve is made of 1fusible metal and. will be destroyed by the fusing of the fusible part.This will ensure that whenever the valve is put into commission it willber.

contain a proper valve mem- The. valve has the advantage of being anextremely eflicient relief valve because of the relative shapes. of thevalve and valve seat, and has the further advantage that if abnormaltemperature develops in the boiler the entire valve will fuse or meltthus relicving the accompanying high pressure.

I claim:

1'. In a relief valve for kitchen boilers and the like, the combinationwith a valve casing havinga sharp edge valve'seat formed by the junctionof two annular surfaces at right angl'esto each other, of a valve havinga conical end which extends partially through the valve seat and whichengages the valve seat edge merely with a line contact, said valve beingformed of fusible metal, the conical portion of the valve which engagesthe valve seat being provided with a jacket of metal harder than thefusible metal and which will not be indentedby the pressure ofthe valveagainst the sharp e"ge valve seat, a spring for holding the valveyieldingly against its seat, said valve having at its upper end arelatively deep recess" to receive the lower end of the spring,saidrecess being of a size to fit the spring, whereby the spring and thewalls of the recess co operate in maintaining the valve in truealignment.

2. In a reliefvalve for kitchen boilers and -the like, the combinationwith a valve casng having a cylindrical inlet which terminates at a fiatsurface and thus presents a right angular valve seat, of a valve'havinga conical end which seats against'the valve seat, there being merely aline contact between the 'valve and valve seat, said valve being formedof fusible metal, the conical portion of the valve which engages thevalve seat being provided with a jacket of metal harder than the fusiblemetal, said valve having at its upper end a spring-receiving recess, aspring guiding pin depending from the top ofthe valve body into therecess,

and a spring for yieldingly holding the valve to its seat, the lowerendof the spring being confined insaid recess and fitting the walls thereofand said pin.

the upper end encircling In testimony whereof, I have signed my I nameto this specification.

EDWARD F. DONNELLY.

